Completion of WWTP expansion design brings St. Louis closer to wet-weather flow goals

Black & Veatch, a global engineering, construction and consulting company, completes design of expansion for Metropolitan St. Louis Sewer District to significantly increase existing peak wet-weather treatment capacity of the Lemay Wastewater Treatment Plant. Project will benefit St. Louis residents not only by enabling MSD to effectively handle expected increases in flow over the next few years but also by increasing plant reliability, flexibility under a range of operating scenarios...

ST. LOUIS, MO, Feb. 27, 2006 -- Black & Veatch, a global engineering, construction and consulting company, announced today that it has completed design of an expansion for the Metropolitan St. Louis Sewer District (MSD) that will significantly increase the existing peak wet-weather treatment capacity of the Lemay Wastewater Treatment Plant. The project will benefit St. Louis residents not only by enabling MSD to effectively handle expected increases in flow over the next few years but also by increasing the Lemay plant's reliability and flexibility under a wide variety of operating scenarios. The expansion will ultimately improve the quality of wastewater discharges and make treatment more efficient.

Expansion of the existing wastewater pump station and 120-million-gallon-per-day (mgd) average daily flow WWTP, which receives flow from both separated and combined sewer systems, has been designed for an initial peak wet-weather treatment capacity of 340 mgd with provisions for expanding to an ultimate treatment capacity of more than 800 mgd.

"Utilities across the United States are challenged to find and implement wet-weather solutions that are both economical and effective," said MSD Director of Operations Dave St. Pierre. "Careful consideration of our options and successful completion of the expansion design bring us closer to our goal of effectively managing the wet-weather flows we receive at our wastewater treatment plants."

Wet-weather treatment options evaluated in a pre-design study and report completed by Black & Veatch in May 2004 included blending, chemically enhanced primary treatment (CEPT), ballasted flocculation, swirl concentrators, on-site storage facilities, and expansion of preliminary and primary treatment facilities. Additional grit removal facilities, primary clarifiers suitable for high-rate clarification such as CEPT, and hydraulic controls comprise the first stage of an expansion that was also designed to accommodate future process modification and phased expansions.

According to Black & Veatch St. Louis Office Manager Tom Ratzki, location of a new outfall for the plant presented special challenges. For example, the project team had to route a 132-inch-diameter outfall across a major north-south railroad line and through a major casino and park development planned for the area between the treatment plant and the Mississippi River. Avoiding a conflict with a future interceptor tunnel planned by MSD similarly presented a planning and design challenge.

"Not only did we need to demonstrate close coordination with a number of agencies and parties involved in planning the development of the casino; but we also needed to be sensitive to the requirements of the railroad, plus coordinate with MSD's own future plans. At times all the parties' needs conflicted, but in the end we agreed on an alternative that was both technically sound and met all parties' basic needs," said Ratzki.
The design also included a plant-wide HVAC system upgrade, odor control, and new piping and flow control between processes to allow flexibility between dry weather and wet-weather operations.

The project is set to bid in early summer 2006.

The Metropolitan St. Louis Sewer District ( is charged with the management of wastewater and stormwater issues for the City of St. Louis and approximately four-fifths of St. Louis County. Covering a service area of approximately 524 square miles, the district operates eight wastewater treatment facilities that treat an average daily flow of over 320 million gallons. Serving one of the country's top 20 metropolitan areas, with a population of approximately 1.4 million residents, MSD operates and maintains one of the oldest and most extensive sewer systems in the United States. The district is responsible for 8,900 miles of sewers -- 2,617 miles of stormwater sewers, 4,495 miles of sanitary sewers and 1,847 miles of combined sewers (combined sewers handle both wastewater and stormwater flows). The age of the sewers maintained by MSD ranges from less than one year old to almost 150 years old, including 524 miles of sewers more than 80 years old and another 311 miles of sewers that were built prior to 1890.

Black & Veatch Corp. ( is a leading global engineering, consulting and construction company specializing in infrastructure development in energy, water, and information and government markets. Founded in 1915, Black & Veatch develops tailored infrastructure solutions that meet clients' needs and provide sustainable benefits. Solutions include conceptual and preliminary engineering services, engineering design, procurement, construction, financial management, asset management, information technology, environmental, security design and consulting, and management consulting services. The employee-owned company has more than 90 offices worldwide. Black & Veatch is ranked on the Forbes "500 Largest Private Companies in the United States" listing.

B&V Water, the water business of Black & Veatch Corp., provides innovative, technology-based solutions to utilities, governments and industries worldwide. Local project teams work in conjunction with a global team of water and wastewater treatment process experts to address site-specific challenges through a broad range of consulting, study, planning, design, and design-build and construction management services.


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